<?php

if (! defined('BASEPATH'))
    exit('No direct script access allowed');

/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package CodeIgniter
 * @author EllisLab Dev Team
 * @copyright Copyright (c) 2006 - 2012, EllisLab, Inc.
 * @license http://codeigniter.com/user_guide/license.html
 * @link http://codeigniter.com
 * @since Version 1.0
 * @filesource
 *
 */
    
// ------------------------------------------------------------------------

/**
 * CodeIgniter Driver Library Class
 *
 * This class enables you to create "Driver" libraries that add runtime ability
 * to extend the capabilities of a class via additional driver objects
 *
 * @package CodeIgniter
 * @subpackage Libraries
 * @category Libraries
 * @author EllisLab Dev Team
 * @link
 *
 */
class CI_Driver_Library
{

    protected $valid_drivers = array();

    protected $lib_name;
    
    // The first time a child is used it won't exist, so we instantiate it
    // subsequents calls will go straight to the proper child.
    function __get ($child)
    {
        if (! isset($this->lib_name)) {
            $this->lib_name = get_class($this);
        }
        
        // The class will be prefixed with the parent lib
        $child_class = $this->lib_name . '_' . $child;
        
        // Remove the CI_ prefix and lowercase
        $lib_name = ucfirst(strtolower(str_replace('CI_', '', $this->lib_name)));
        $driver_name = strtolower(str_replace('CI_', '', $child_class));
        
        if (in_array($driver_name, 
                array_map('strtolower', $this->valid_drivers))) {
            // check and see if the driver is in a separate file
            if (! class_exists($child_class)) {
                // check application path first
                foreach (get_instance()->load->get_package_paths(TRUE) as $path) {
                    // loves me some nesting!
                    foreach (array(
                            ucfirst($driver_name),
                            $driver_name
                    ) as $class) {
                        $filepath = $path . 'libraries/' . $lib_name .
                                 '/drivers/' . $class . '.php';
                        
                        if (file_exists($filepath)) {
                            include_once $filepath;
                            break;
                        }
                    }
                }
                
                // it's a valid driver, but the file simply can't be found
                if (! class_exists($child_class)) {
                    log_message('error', 
                            "Unable to load the requested driver: " .
                                     $child_class);
                    show_error(
                            "Unable to load the requested driver: " .
                                     $child_class);
                }
            }
            
            $obj = new $child_class();
            $obj->decorate($this);
            $this->$child = $obj;
            return $this->$child;
        }
        
        // The requested driver isn't valid!
        log_message('error', "Invalid driver requested: " . $child_class);
        show_error("Invalid driver requested: " . $child_class);
    }
    
    // --------------------------------------------------------------------
}
// END CI_Driver_Library CLASS

/**
 * CodeIgniter Driver Class
 *
 * This class enables you to create drivers for a Library based on the Driver
 * Library.
 * It handles the drivers' access to the parent library
 *
 * @package CodeIgniter
 * @subpackage Libraries
 * @category Libraries
 * @author EllisLab Dev Team
 * @link
 *
 */
class CI_Driver
{

    protected $parent;

    private $methods = array();

    private $properties = array();

    private static $reflections = array();

    /**
     * Decorate
     *
     * Decorates the child with the parent driver lib's methods and properties
     *
     * @param
     *            object
     * @return void
     */
    public function decorate ($parent)
    {
        $this->parent = $parent;
        
        // Lock down attributes to what is defined in the class
        // and speed up references in magic methods
        
        $class_name = get_class($parent);
        
        if (! isset(self::$reflections[$class_name])) {
            $r = new ReflectionObject($parent);
            
            foreach ($r->getMethods() as $method) {
                if ($method->isPublic()) {
                    $this->methods[] = $method->getName();
                }
            }
            
            foreach ($r->getProperties() as $prop) {
                if ($prop->isPublic()) {
                    $this->properties[] = $prop->getName();
                }
            }
            
            self::$reflections[$class_name] = array(
                    $this->methods,
                    $this->properties
            );
        } else {
            list ($this->methods, $this->properties) = self::$reflections[$class_name];
        }
    }
    
    // --------------------------------------------------------------------
    
    /**
     * __call magic method
     *
     * Handles access to the parent driver library's methods
     *
     * @access public
     * @param
     *            string
     * @param
     *            array
     * @return mixed
     */
    public function __call ($method, $args = array())
    {
        if (in_array($method, $this->methods)) {
            return call_user_func_array(array(
                    $this->parent,
                    $method
            ), $args);
        }
        
        $trace = debug_backtrace();
        _exception_handler(E_ERROR, "No such method '{$method}'", 
                $trace[1]['file'], $trace[1]['line']);
        exit();
    }
    
    // --------------------------------------------------------------------
    
    /**
     * __get magic method
     *
     * Handles reading of the parent driver library's properties
     *
     * @param
     *            string
     * @return mixed
     */
    public function __get ($var)
    {
        if (in_array($var, $this->properties)) {
            return $this->parent->$var;
        }
    }
    
    // --------------------------------------------------------------------
    
    /**
     * __set magic method
     *
     * Handles writing to the parent driver library's properties
     *
     * @param
     *            string
     * @param
     *            array
     * @return mixed
     */
    public function __set ($var, $val)
    {
        if (in_array($var, $this->properties)) {
            $this->parent->$var = $val;
        }
    }
    
    // --------------------------------------------------------------------
}
// END CI_Driver CLASS

/* End of file Driver.php */
/* Location: ./system/libraries/Driver.php */